CASE                               37                               

A 37-year-old, right-hand-dominant male is referred to the emergency department after sustaining a ring avulsion amputation of his left ring finger (Fig. 4–20A and B). He has mild hypertension, smokes cigarettes occasionally, and works in construction. He sustained the injury while climbing a tree during a hunting expedition, and arrives with the amputated part wrapped in moist gauzed and placed on ice. On examination, the patient has a complete amputation of the soft tissue of the ring finger at the level of the MP joint with preservation of the flexor tendons and extensor mechanism. X-rays demonstrate a subtle fracture of the distal phalanx but no other bony injury (Fig. 4–20C).

Figure 4–20 A–B

Figure 4–20 C

Which of the following is the appropriate Kay classification of this injury?

1. Class I

2. Class 2

3. Class 3

4. Class 4

Discussion

The correct answer is (C). The Kay classification is utilized for the diagnosis and management of ring avulsion injuries. This patient would be classified as Class/Grade 3, which is a complete degloving or complete amputation. Class 1 injuries are avulsion injuries with adequate circulation. Class 2 injuries have arterial compromise only. Class 3 injuries have inadequate circulation with bone, tendon, or nerve injury, and Class 4 injuries represent a complete degloving or complete amputation.

The patient desires all attempts at replantation, even after learning of the lengthy hospital course, requisite postoperative therapy, and possibility of replant failure.

Which of the following factors presents the greatest challenge to performing successful replantation?

1. Absence of significant bony injury

2. Avulsion mechanism of injury

3. Technical challenge of repairing small vessels with operating microscope

4. Age of the patient

5. Amputation level at the MP joint

Discussion

The correct answer is (B). There are many determinants of success during attempted replantation of amputated digits. One important prognostic factor is the mechanism of injury: avulsion amputations have been demonstrated to have a lower success rate than sharp amputations. In general, factors favorable to viable replantation include sharp mechanism of injury, proximal level of amputation, short duration of ischemia, appropriate preservation of the amputated part, and good overall health of the patient with normal platelet count.

Replantation proceeds uneventfully with the use of a vein graft from the volar forearm. On POD 3, the patient’s finger becomes increasingly edematous, with violaceous discoloration and capillary refill <1 second.

Which of the following interventions is NOT appropriate at this stage?

1. Immediate return to the operating room for exploration and additional venous anastomosis

2. Removal of the nail plate with application of heparin-soaked gauze to increase efflux of congested blood from the finger

3. Application of medicinal leeches to augment venous outflow

4. Observation only

5. Further discussion with the patient about the option of operative exploration and possible failure of replantation

Discussion

The correct answer is (D). This finger demonstrates signs of venous congestion, which will likely result in failure of replantation unless addressed expeditiously. This can be treated by a variety of different means, including return to the operating room for exploration and provision of additional venous drainage, as well as attempts to augment venous outflow using leeches or topical heparinized saline. In addition, given the single digit nature and mechanism of this injury, it is reasonable

to discuss all options with the patient at this stage including the possibility of replant failure.

Leeches are applied with improvement in the color and turgor of the replanted finger.

What is the name of the bacteria present in medicinal leeches and what is the appropriate antibiotic prophylaxis?

1. Aeromonas hydrophila and penicillin

2. Aeromonas hydrophila and ciprofloxacin

3. Hirudo medicinalis and penicillin

4. Hirudo medicinalis and ciprofloxacin

5. Hirudo medicinalis and tetracycline

Discussion

The correct answer is (B). The primary bacteria found in medicinal leeches are Aeromonas hydrophila, and the antibiotic treatment of choice is ciprofloxacin. The name of medicinal leeches is hirudo medicinalis. Other antibiotics which can be used for prophylaxis are trimethoprim/sulfamethoxazole and tetracycline; Aeromonas hydrophila is often resistant to penicillin.

Objectives: Did you learn...?

Describe the Kay classification?

Pinpoint th challenges that affect outcome in replant failure? Identify the signs of venous congestion?

Treat venous congestion?

Describe the complications of leeching?